I have both Greeks and Persians in 25mm, although most are not painted. I could get them out for a game some time if you don't mind playing with largely undercoated figures
If you are looking for 1/72nd scale Greeks go to the Plastic Soldier Review & you will get a list of who makes what including a review of what you get in each box Persians Greeks & HAT indutries now do Spartans I believe. ( also WW2 Russians to add to your WW2 radio operators) The Greek army is fairly slow if you go for an army based on Hoplites but it can have a fair amount of good light infantry too including Peltasts, what it lacks is any real numbers of cavalry but with the best infantry in the world who needs them. Also on the plus side its great fun to paint & looks good on mass with lots of diffrent shield paterns.
Why not try a 10mm army loads of figs for little cost and easy to paint
http://www.pendraken.co.uk/ £33.50 gives a 1000 point army (over 300 fiigs) I have 10mm romans, ancient brits, and palmyran
Capt in the 4th japatti regt, Biryani Brigade 4th vindaloo division